Drive mechanism.



H. GROB.

DRIVE MECHANISM.

APPLICATION FILED JAN- 9-1911- RENEWED MAR- 5. I918.

1,2613% Emma Apr. 2,1918.

of the dynamo,

in snares ra rnnr cannon.

HUGO GROB, 0F ZURICH, SWITZERLAND, ASSIGNOR TO JULIUS PINTSCH AKTIEN- GESELLSCHAFT, 0F BERLIN, QEBMANY.

DRIVE MECHANISM.

Application filed January 9, 1911, semi No. 601326.

This invention relates to a drive mecha-' nism, and with regard to certain more specific features, to apparatus suitable for driving a train-lighting dynamo from a car axle.

The invention has for one object the provision of a'drive mechanism which will be at once efficient, durable and dependable in operation.

Another object of the invention is thepro-l vision of improved meanswhereby the tension on the belt or other power-transmitting medium may be influenced by the weight of the dynamo. 4

Another object is the of a spring,

for maintaining thebelt taut.

Another object is the provision of a simple and reliable means for automatically keeping constant the belt tension, irrespective of the lengtheningof the belt.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations or elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the application of which will be indicated in the following claims.

In the drawings, in which are shownone or more of variouspossible embodiments of Figure 1 is a diagrammatic representation of the invention used in connection with a tension spring;

Fig. 2 is a similar diagram showing the employment of a-compression spring;

Fig. 3 is a further modification, illustrating a dynamo mounted above its point of support, and v Fig shows a modificationwherein both ends of the spring are movable.

Similar reference characters refer to simi-' lar arts throughout the different views of the rawings.

Referring now to Fi sented at A, is suspen ed from-the pivot with the line connecting the center of grew 1, a dynamo, repreractical utilization in conjunction with the weightvand therefore the belt tension,

B due to the weight of Specification of Letters Patent. Pwtgntgd Apr, 2, 191%,

Renewed March 5, 1918. Serial No. 220,619-

ity of the dynamo and the point of support B making an angle a to the vertical. lhe dynamo is driven by a belt D passing around the pulley R and deriving its power from one ofithe car axles. It is obvious that the dynamo tends to rotate counter-clockwise about its point of suspension B; considering the case as a simple pendulum, the force'ot' restitution would be equal to Wsinot, where W is the weight ofthe dynamo and a the angular displacement from the vertical of.

the line connecting the center of gravity of the dynamo with the point of support B. For practical purposes the belt tension, due to the weight of the dynamo, may be considered as proportional to the moment of force W X a, where a is the horizontal component' of the distance from the center of gravity of the dynamo to the point of sup port B. As the belt lengthens the distance a varies, and in order to automatically maintain the belt-tension constant, 1 cause the belt tension to be afiected by a second moment of force which varies in such a waythat the algebraic sum of the two moments, is maintained at. a predetermined value'. lhis object may be attained in various ways, and I have illustrated in the drawings a spring for this purpose. In Fig. 1 the tension spring F is mounted in such a way as to add to the belt? tension due to the weight of the dynamo to an extent proportional to thestrength of the and the parts are so proportioned that the decrease of belt-tension due to the decrease era as the dynamo swings counter-cloclrwise, is ofiset by a corresponding increase in the belt-tension due to the spring F, owing to the increase ot'the moment arm 7). l t is true that the variations in these two moments probably do not balance each other with mathematical precision, but for all practical purposes the belt-tension may be said to be a constant quantity. i K It is not necessary that a tension spring be employed. In Fig. 2 l have illustrated a compression spring F aiding the efiect of the weight of the dynamo and increasing in its efi ect on the vbelt-tension as the effect the dynamo decreases. distance a in Fig. 2 may be If desired, th

are

increased by swinging the dynamo c1001;- wise until the center lin of the spring is I above the point of suspension B, in which case the spring would initially oppose the weight of the dynamo; then as the belt lengthens a decrease of the distance a would be accompanied by a decrease in the distance 6 until the effect of the spring becomes zero, and thereafter, as the distance 6 increases with opposite sign, the spring would aid the weight of the dynamo to an increasing extent proportional to the continually decreasing effect of the weight of the dynamo.

The dynamo need not be suspended as in Figs. 1 and 2. Thus in Fig. 3 is illustrated a dynamo mounted above its point of support so that a lengthening of the belt is accompanied by an increase in the belt-tension due to the weight of the dynamo, together with a corresponding decrease in the effect of the tension spring F.

The invention may also be exemplified in a device in which the spring is not fixed to the truck at either end, thus making it possible to vary more rapidly the efiect of the spring on the belt-tension. In Fig. 4 the spring F is fastened at one end, as before, to the dynamo frame at L, but the other end, is secured to the end N of a lever M pivoted to the car truck at K. The lever is so connected with the dynamo frame that, as the belt becomes longer, not only will the end of the spring attached to the dynamo frame at L move upwardly, but also th other end, at N, and thus a considerably more rapid increase of the distance 6 is attained than is the case in Figs. 1, 2 and 8.

' Stated briefly, the illustrated embodiments of the invention comprise a belt drive for a dynamo so mounted that its weight influences the belt-tension; and any variations in the effect of this weight on the belt-tension are offset by equal and opposite variations in the effect on said tension ofa spring. As many changes could be made inthe above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting-sense.

It is also to be understood that the language used in the following claims is in tended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which," as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters .Patent is: v

1. In a drive mechanism, in combination,

a belt, means adapted to influence the belt tension, and means adapted to automatically offset variations in the effect of said first means on said belt tension.

2. In a drive mechanism, in combination, a belt, a driven member, and a spring, said driven member and saidspring being cooperatively related to each other to automatically maintain constant the tension of said belt.

3. In a drive mechanism, in combination, a belt, a dynamo held in equilibrium by the tension of the belt, and a spring cooperating with the dynamo and adapted automatically to maintan constant the belt tension.

4. In a drive mechanism, in combination, a belt, a dynamo, means whereby the weight of the dynamo influences the belt tension, and means for automatically compensating for variations in the effect of said weight on said tension.

5. In a drive mechanism, in combination, a belt, a dynamo, means for supporting the dynamo whereby the weight of the dynamo influences the belt tension, and means for automatically compensating for variations in the effect of said weight on said tension.

6. In a drive mechanism, in combination, a belt, a dynamo, a pivotal mounting for the dynamo whereby the weight of the dynamo influences the belt tension, and means for automatically compensating for variations in the effect of said weight on said tension.

7. In a drive mechanism, in combination, a belt, a dynamo, means whereby the weight of the dynamo influences the belt tension, and means adapted to influence the belt tension, said second means adapted to cooperate with the dynamo to maintain the belt tension substantially independent of variations in the length of the belt.

8. In a drive mechanism, in combination, a belt, a dynamo, means whereby the weight of the dynamo influences the belt tension,

and means comprising a spring for auto-. matically compensating for variations in the effect of said weight on said tension.

9. In a drive mechanism, in combination, a belt, a dynamo the weight of which is adapted to influence the belt tension, a

spring, means for mounting the spring so that variations in the efi'ect of the weight of the dynamo on the belt tension are compensated for by variations in the effect of the spring on said tension.

10. In apparatus of the character described, in combination, a dynamo, a driving belt therefor, means including a pivotally mounted element whereby the weight of the dynamo affects the belt tension, and a device connected to said element for also affecting the belt tension, the aforesaid parts being so disposed that as said element moves the distance-of the line of the force exerted by said device from the axis of aid element is I the axis of said element 1s neon/ac the efiect of changed to compensate for the weight variations in belt tension due to of said dynamo.

11.'In apparatus of the character described, in combination, dynamo, a driving belt therefor, means including a rotatable element wherebythe weight of the dynamo affects the belt tension, and a device connected to said element for also affecting the belt tension, the aforesaid parts being so disposed that as said element rotates in one or the other direction the distanceof the line of the force exerted by said device from correspondingly increased or decreased in a manner to compensate for the efiect of variations in belt tension due to the weight of said dynamo.

12. In apparatus of the character described, in combination, a dynamo,.a driving belt therefor, means whereby the Weight of the dynamo affects the belt tension, includ- .ing a pivoted member forming a supporting element for the dynamo, andga device connected to said member and adapted to afiect the belt tension, the aforesaid'parts being so disposed that as said member rotates the distance ofthe line of the force exerted by said device from the axis of said member is varied in a manner eflect of variations in belt tension due to the weight of said dynamo.

13. In apparatus of the character described, in combination, a dynamo, a belt adapted to drive the same, means whereby the weight of the dynamo adects the belt tension comprising a rotatable member forming a supporting element for the dynamo, a device connected to said member and adapted to afiect the belt tension, the aforesaid parts being so disposed that as said member rotates in one or the other direction theefi'ective angle of the line of the force exerted by said device with respect to the axis of said member is respectively increased or decreased in a manner to compensate for the efiect of variations in belt tension due to the weight of said dynamo.

14. In apparatus of the character described, in combination, a dynamo, a belt adapted to drive the same, a spring cooperatively associated with the belt to afiect the belt tension, means whereby the weight of the dynamo afi'ects the belt tension comprising a rotatable element? connected to the spring and serving as a support for said dynamo, said spring and said rotatable element being so related that variations inbelt tension caused by the efiect ofthe weight of the dynamo are compensated for by variations in the efi'ect of the spring.

15. In apparatus of the character described, in combination, a driven member, a belt adapted to drive the-same, a rotatable body connected with said driven member,

and a spring connected to said body and so to compensate for the tion, a belt, a device adapted to ,said points being member is adapted to compensate at times for the efi ect of varlations 1n the modisposed that as the body rotates the line;

of the force exercised by the spring changes its distance from the axis of the rotatable body in such manner thatthe belt tension will be maintained constant.

16. In apparatus of the character described, in combination, a dynamo, a belt adapted to drive the same, a rotatable body connected with the dynamo, a spring connected'to said body and adapted to affect the tension on the belt, and so disposed that as the belt elongates the distance of the line of the force of the spring from the axis of the rotatable body changes in such manner that the belt tension will remain substantially constant.

1?. In apparatus of the character described, in combination, a dynamo, a belt H adapted to drive the same, a rotatable body connected with the dynamo, a spring connected to said body and adapted to afl'e'ct the tension on the belt, and so disposed that as the belt elongates the line of the force exercised by the spring increases in distance from the axis of the rotatable body.

18. In apparatus of the character deseribed,.in combination, a driven member, a belt adapted to drive the same, a rotatable body forming a supporting element for said driven member, and a spring connected to said body adapted to afl ect the belt tension, and so disposed that as the belt elongates the distance of the line of the force of the spring in distance from the axis of the rotatable body. v '20. In a driving mechanism, in combinabe driven thereby, a pivoted suspension member upon which said device is carried, an arm attached to said suspension member, and a spring attached at one end to said arm and ada ted to compensate for variations in tens on of said belt caused by difierent positions of said pivoted suspension member.

21. In a device of the character described, in combination, a suspension member, a pivot therefor, a dynamo carried thereby, a belt for imparting motion to said dynamo, and a spring attached to a point on said suspension member and to an external point, so related that the eflective moment of the force of said spring on saifi ment of the weight of said dynamo about a driving member, a driven member, a belt said pivot.

22. In a device of the character described, in combination, a suspension member, a pivot therefor, a dynamo carried thereby, a belt for imparting motion to said dynamo, and, a spring connected to said member so that the moment of force of said spring about said pivot shall at all times compensate for variations in the moment of the weight of said dynamo about said pivot in order that the tension of said belt may be maintained constant.

23. In a drive mechanism, in combination, a driven member, a belt for driving the same, means whereby the weight of said driven member influences the tension of said belt, and a second means adapted to infiuence the tension of said belt, said second means being adapted to automatically compensate for variations in the efiect of said weight upon the tension of said belt.

24. In a drive mechanism, in combination, a driving member, a member to be driven, said members being movably mounted relatively to each other, a driving belt connecting said members, one of said members being mounted so that movement relative to the other member varies the moment of the weight of said movable member, and means adapted to oifset variations in the effect of the weight of said movable member upon the tension of said belt.

25. In a drive mechanism, in combination,

connecting said members, and means whereby the conjoint action of a mechanical force and the weight of said driven member counteract variations in length of the belt so as to produce a constant tension of the latter.

26. In a drive mechanism, in combination, a driving member, a driven member, a belt connecting said members, and means where by the conjoint action of a mechanical force and the weight of said driven member counteract variations in the position of the driving and driven members relative to each other so as to produce a constant tension of the connecting belt.

27. In a mounting for railway-car lightin'g-dynamos, in combination, means for supporting a dynamo to allow. limited movement thereof toward or from its driving element, a driving belt for said dynamo, and means including a spring mounted for control by the said movement of the dynamo to tend to counteract the effect of said movement on the tension, of said belt for thereby tending to maintain said tension constant.

In testimony whereof I aflix my signature in the presence of two witnesses.

nneo once.

Witnesses WOLDEMAR HAUPT, HENRY HAsrER. 

